The disclosure relates to a method for releasing platelets from megakaryocytes contained in a fluid (F), the method being carried out by means of a system comprising two concentric cylinders, an inner cylinder comprising a cylindrical wall and a hollow outer cylinder located radially external to the inner cylinder, the outer cylinder comprising a cylindrical wall of a base at which the second cylinder is closed, the cylinders being separated by a space devoid of any mechanical parts, the space being intended to receive the fluid (F), the method comprising the following steps: supplying the space with a fluid (F) comprising megakaryocytes, rotating the inner cylinder about its axis, the outer cylinder being stationary, or moving the two cylinders in opposite directions about their axes, so as to generate an at least partially turbulent flow of fluid (F) in the space and obtain a second fluid (F′) enriched in platelets.